No, I don't presume this. But I've seen, countless times, black people cry racism in cases where racism was obviously not the issue. Bonaly's story is just one public example of this. But I don't think a single black person can honestly say they don't know people like this in their own lives.
You mention black people's need to be hyper aware. But I think this is exactly the problem. There's a trauma response known as hypervigilance. When somebody goes through something awful, they sometimes go through a period where they're hypersensitive to other potential dangers.
Sometimes they'll be afraid to leave the house or flinch at the slightest noise or become paranoid of anybody who shares any similarity to the person who traumatised them. Therapists work very hard to help survivors work through this.
I think some black people experience something similar. Only, in this case, they often haven't been through the traumatic experience themselves. And nobody is trying to help them work through it. Instead, they've been told, over and over again that they're under siege. Until they believe it.
Again, to be clear, this isn't to say that racism and racial trauma no longer exist in their own right. I've experienced racism too. It's to say that many of the people being most fatalistic about racism and white supremacy live lives that directly contradict their narrative. They're surrounded by examples that contradict that narrative. I think it would be better for all concerned if they could acknowledge the good in their lives and in society as well as the bad.